Exodus 12:7, 11-12

And they shall take of the blood, and put it on the two side-posts and on the lintel, upon the houses wherein they shall eat it.

And thus shall ye eat it: with your loins girded, your shoes on your feet, and your staff in your hand; and ye shall eat it in haste: it is Jehovah’s passover. For I will go through the land of Egypt in that night, and will smite all the first-born in the land of Egypt, both man and beast; and against all the gods of Egypt I will execute judgments: I am Jehovah.